Congressional investigations have a way of stretching from months to years, but the House committee probe into 2012's Benghazi attack was especially lengthy. At two years and four months, it was longer than congressional probes into 9/11, Watergate, the JFK assassination and Pearl Harbor.

Four Americans died at the U.S. Embassy in Libya.

Republicans launched the investigation with a focus on Hillary Clinton, but Democrats accuse them of using Benghazi as a political weapon, especially after this comment from Republican leadership:

"Everybody thought Hillary Clinton was unbeatable, right?" Rep. Kevin McCarthy asked on Fox News. "But we put together a Benghazi special committee, a select committee. What are her numbers today?"